Variable condenser



Aug. 24 1926.

L. A. HAMMARLUND VARIABLE CONDENSER 7 Filed Fb. 14: 1924 2 Sheets-Sheet1 INVENTOR ATTORNEYS Aug. 24,1926. F 1,596,875

L. A. HAMMARLUND VARIABLE connsusnn Filed Feb. 14. 1924 2 sheets shget 2Patented Aug. 24, 1926.

UNITED STATES 1,596,875 PATENT OFFICE.

LLOYD a HAMMARLUND, or NEw YORK, N. Y., assreNon T HAMMANLUND MFG.COMPANY, INc.,or NEW YORK, N. Y., A CORPORATION or NEw YORK.

VARIABLE CONDENSER.

Application filed February 14, 1924. Serial No. 692,733. I

My invention comprises certain improvements applicable to electriccurrent controlling instruments generall and certain improvements moreparticu arly applicable to the variable condenser which forms thesubject matter of my copending ap lication filed November 28th, 1922,Serial 70. 603 793; in which a primary means is employed to bring thecondenser into approximate adjustment" and a secondary means workingthrough the primary means, is employed to bring the condenser into amore accurate adjustment.

'A practical embodiment of my invention is represented in theaccompanying drawings, in which- I I ig. 1 represents the condenser intop P 311? 2 represents the condenser in side elevation.

Fig, 3 represents a section taken in the plane of the line III-III ofFig. 1, looking 1n the direction of the arrows. I

Fig. 4 represents a back view of the conden r.

Fig. 5 represents a section taken in the plane of the line VV of Fig. 1,looking in the direction of the arrows. I

Fig. 6 represents a detail section on an enlar ed scale, taken in theplane of the line VI of Fig. 5, looking in the direction of the arrows.

The spaced stationary and movable condenser plates are denoted by 1 and2 respectively. The stationary condenser plates have a two post supportas follows: I

The front and back frame plates 3 and 4 have side recesses 5, 6 and 7,8. Insulating bars 9, 10 span the side recesses 5, 6 and are permanentlysecured to the front frame plate 3 as, for instance, by rivets 11.Insulating bars 12, 13 span the side recesses 7, 8, and are permanentlysecured to the back frame plate 4 as, for instance, by rivets 14. Thestationary condenser plate carrying posts are denoted by 15, 16, whichplates are secured at their ends by screws 15* 16* to their respectiveinsulating bars 9, l2 and 10, 13, at points opposite the side recessesin the front and back frame plates. These posts are kerfed at regularintervals and the edges of the stationary condenser plates are insertedinto said kerfs and soldered, thereby roducing an accurate and rigidspacing o the plates and eliminating the necessity of using spacingwashers on the posts. This two post support for the stationary platesalso materially simplifies the construction of the condenser.

' The movable condenser plate carrying rock shaft comprises the enlargedintermediate portion 17 and the reduced end portions 18, 19, the ends ofthe enlarged intermediate portion 17 being provided with conicalportions 20, 21. Hollow bearings 22, 23 surround the reduced portions 18and 19 of the rock shaft and are screw-threaded into their respectivefront and back frame plates 3 and 4. These bearings have conical seats24, for the conical ends of the enlarged intermediate portion 17 of therock shaft. The enlarged intermediate portion 17 of the rock shaft iskerfed at regular intervals and the inner edges of the movable platesare forced into said kerfs and S0].- dered, thereby producing anaccurate and rigid spacing of the plates.

Means are provided for exerting more or less frictional resistance tothe turningof the rock shaft and for adjusting the rock shaftlongitudinally, which means in the present instance comprises spanners26, 27 engaging the bearings 22, 23, to screw them inwardly or outwardlyin their respective front and backframe plates 3 and 4, said spannersbeing provided with elongated concentric grooves 28, 29, through whichclamp screws 30, 31 pass into the front and back frame platerespectively for locking the spanners and thereby the bearings in theiradjusted position.

cans are provided for maintaining a good electrical connection betweenthe rock shaftand one of its bearings, which means in the presentinstance comprises a spring element carried by the rock shaft having aself-cleaning wiping contact with the bore of one of said bearings. Thisspring element is shown as comprising a body portion 32, having springarms 33, 34 provided with wings 35, 36 at their ends, the body portion32 being soldered or otherwise secured to. the reduced end 19 of therock shaft with its wings 35, 36 arrangedto wipe the bore of the bearing23.

. The reduced end 18 of the movable condenser plate carrying rock shaftprojects forwardly through the panel 37 where it is provided with theusual dial 38 and knob 39, acting as the primary means for bringing thecondenser into approximate adjustment.

The condenser frame is supported by and spaced from the panel 37, in thepresent instance by providing the front frame plate 3 with studs i0engaged by the screws il.

The secondary means for bringing the condenser into a more accurateadjustment is constructed, arranged and operated as follows:

The radially disposed arm -12. is located between the front. frame plate3 and the panel, the inner end of which arm is provided with a clamp a?)frictionally embracing the reduced end 18 of the rock shaft, thebranches -l-t and T5 of which clamp are engaged by a screw to to drawthe clamp into the required frictional engagement with the rock shaft.

The outer end of this arm -12 is provided with a yoke, the branches -17,d8 of which engage the opposite sides of an eccentric cam t), fixed to asecond rock shaft 50, which rock shaftis provided with a socket 51projecting through the panel 37 in position to removably receive theshank of a handle 52, as desired. The handle may be moved in eitherdirection to move the cam to swing the arm 42 for turning the movablecondenser plate rock shaft.

The cam 49 is made radially adjustable so as to accommodate the same todifferent diameters of dials, the means for radially ad justing the cambeing, in thepresent instance constructed as follows:

The bearing 5% for the cam shaft 50 is clamped in any desired positionalong the radial groove 55, in the bottom of the front frame plate 3, byproviding the bearing of one side with a collar and the other side witha nut and washer 57. It will be understood that the hole 58, through thepanel 37, through which the cam shaft extends is also suitably elongatedto permit this radial adjustment of the cam. lVhen it is desired toadjust the condenser, the knob 39 is turned, as is usual, to bring thecondenser into approximate adjustment; it being understood that the rockshaft turns in the clamp of the arm e2. After this approximateadjustment has been obtained, an extremely accurate adjustment of thecondenser may be obtained by manipulating the cam operating handle tomove the cam and rock the arm, and thereby the movable condenser platerock shaft either way, to bring the adjustment slightly up or down, asthe case may require.

From the above description it will be seen that I have produced aninstrument in which the stationary condenser plates and also the radialcondenser plates are accurately and rigidly spaced apart novel meansbeing provided for adjusting the bearings to obtain the proper rotativefrictional resistance for the rock shaft and fo' adjusting the shaftlongitudinally to accurately space the movable condenser plates from thestationary condenser plates.

Also novel means are provided for maintaining a good electric connectionbetween the rock shaft and one of its bearings by the self-cleaningwiping device. Also means are providedfor radially adjusting the cam soas to properly position its operating handle with respect to dials-0fdifferent diameters.

It is evident that various changes may be resorted to in theconstruction, form and arrangement of the several parts withoutdeparting from the spirit and scope of my invention; hence, I do notwish to be limited to the particular embodiment herein shown anddescribed, but- Yfhat 1 claim is 1. In a variable condenser, spacedstationary and movable plates, means including the movable platecarrying rock shaft for bringing the condenser into adjustment, andseparate adjusting devices engaging the shaft upon opposite sides of theplates for adjusting the frictional turning resistance of the rock shaftand the rock shaft longitudinally to bring the movable plates intoproper spaced relationship to the stationary plates.

1n variable condenser, spaced stationary and movable plates, meansincluding the movable plate carrying rock shaft for bringing thecondenser into adjustment, bearings for said rock shaft upon oppositesides of the plates, and'means for independently ading the hearings tobring the movable plates into proper spaced relationship to thestationary plates and to adjust the frictional resistance of said shaft.

3. In a variable condenser, spaced station ary and movable plates, meansincluding the movable plate carrying rock shaft for bringing thecondenser into adjustment, front and rear frame plates, shaft bearingsscrewthreaded therein, and rotatable spanners engaging said bearings forturning them to adjust the frictional turning resistance of the rockshaft and the position of the rock shaft longitudinally, to bring themovable plates into proper spaced relationship to the stationary plates.

a In a variable condens r, spaced stationary and movable plates, meansincluding the movable plate carrying rock shaft for bringin ac condenserinto adjustment, front and rear frame plates. shaft bearings screW-threaded therein, rotatable spanners engaging said bearings for turningthem to adjust the frictional turning resistance of the rock shaft andthe position of the rock shaft longitudinally, to bring the movableplates into proper spaced relationship to the stationary plates. andmeans for locking the spanners in their adjusted position.

5. In a va i: ble condenser, spaced station ary and movable plates, andmeans including the movable plate carrying rock shaft for bringing thecondenser into adjustment, said rock shaft having an enlargedintermediate portion provided with conical ends, bearings surroundingthe shaft and having conical seats for receiving said conical'ends, anda device carried by the rock shaft having a self-cleaning wiping contactwith the bore of one of said hearings to maintain a good electricalconnection between the shaft and bearing.

6. In a "ariable condenser, spaced stationary and movable plates, andmeans including the movable plate carrying rock shaft for brin ing thecondenser into adjustment, said rocer shaft having an enlargedintermediate portion provided with conical ends, bearings surroundingthe shaft and having conical seats for receiving said conical ends, anda spring element carried b the rock shaft having a self-cleaning wipingcontact with the bore of one of said hearings to maintain a goodelectrical connection between the shaft and bearin In testimony, that Iclaim the foregoing as m invention, I have signed my name this 8th dayof February, 1924.

LLOYD A. HAMMARLUN D.

